Hypodermic syringe and cartridge



Nov. 24, 1964 s. MYERSON ETAL HYPODERMIC SYRINGE AND CARTRIDGE INVENTORSMYERSON L. MYERSON SIMON RICHARD Mg Wham Filed June 14, 1961 ATTORNEYS3,158,155 HYPODERMIC SYRINGE AND CARTRIDGE Simon Myerson and Richard L.Myerson, Newton, Mass, assignors to Myerson Tooth Corporation,Cambridge, Mass., a corporation of Massachusetts Filed June 14, 1961,Ser. No. 117,055 9 Claims. (Cl. 128-215) The present invention relatesto an improvement in hypodermic syringes and cartridges which, when saidsyringes and cartridges are used together with sterilized needles of theconstruction described in co-pending application Serial No. 835,802, nowPatent No. 3,055,364, filed by Simon Myerson and Richard L. Myerson,provide protection against infection due to contamination of thesterilized needle even though the syringe with which the sterilizedcartridge and needle are used is not com pletely sterile.

In recent years much progress has been made towards eliminating thehazards of infection from hypodermic injections by the increasing use ofpresterilized and sterile packaged disposable needles. However, with theusual construction, these disposable needles do not provide protectionagainst failure to completely sterilize a syringe or contamination ofthe syringe after sterilization and prior to its use.

The needle described in said co-pending application is provided with asleeve attached slidably but snugly over the cartridge entrant end. Thissleeve guides the needle through needle receiving passage in the tip ofthe syringe to the center of the puncturable end cap of the sterilizedcartridge which contains a medicant that is to be injected. Thesterilized sleeve is inserted with the cartridge entrant end of thesterilized needle through the needle receiving passage of the syringe tothe puncturable cap of the sterilized cartridge and consequentlyprotects such entrant end against any contact with the syringe. Theneedle is preferably sterile packaged with the sleeve thereon.

Contact of the end of the sleeve with the puncturable cap of thesterilized cartridge (1) during insertion of the sterilized needle andsleeve into the loaded syringe (loaded with the cartridge) or (2) duringinsertion (loading) of the sterilized cartridge in the syringe after theneedle with the sleeve over the entrant end thereof has been insertedthrough the needle receiving passage in the syringe tip to its ultimateposition in the unloaded syringe, forces the sleeve to slide back on theneedle and the sharp entrant end of the sterilized needle to puncturethe central portion of the cap. Thus, the entrant end of the sterilizedneedle, which enters the sterilized cartridge and is exposed to itssterilized contents, does not contact the syringe at any time. Itcontacts only the central portion of the sterilized puncturable end capof the cartridge and consequently it is not contaminated even if thesyringe is not completely sterile provided that e the central portion ofthe cap is not contaminated.

There are two widely used types or" syringes, the breech type and thewindow type. The puncturable central area of the cartridge may becomecontaminated in the breech type of syringe which is loaded through theupper end of the barrel thereof, by contact with the rim of the barreland also, it may be contaminated when seated at its ultimate position atthe bottom of the barrel. This is particularly true if the bottom of thebarrel is of the usual construction and the closure cap is also of theusual construction described hereinafter. Contamination is almostcertain if some globules of moisture are present at the bottom of thebarrel at the time of the insertion of the cartridge and the floor iscontaminated. In the window type of syringe which has a window along itslength permitting the insertion and positioning of the United StatesPatent 3,158,155 Patented Nov. 24, 1964 cartridge through the window,since such windows are usually arched at the bottom, the risk ofcontamination is less when the cartridge is being introduced in thewindow than when the cartridge is being inserted in the breech type ofsyringe. However, the risk of contamination by the floor is the same.

An object of this invention is to eliminate or to greatly reduce thehazard or" contamination of the critical area of the cartridge cap whenit is being inserted into the barrel. This objective can be accomplishedby certain changes in the cartridge alone. Even greater protection canbe provided by certain changes in the syringe. A combination of thesechanges in the syringe and in the cartridge is believed to offer maximumprotection.

The usual closure cap is convex and comprises a metal outer shell withan end wall having a hole in its center. A very thin disc of aluminum isplaced over the hole and a rubber sealing element is placed on top ofthe aluminum disc, then the closure cap is clamped onto the cartridgeend. Some closure caps omit this disc and the sealing rubber or othermedium is exposed. The needle passes through the hole and punctures thedisc and the sealing element in the former case or through the hole andthe seal in the latter case.

The closure cap of the present invention comprises a shell made of asuitable metal, e.g. aluminum, and having a smooth puncturable end wallwhich is concaved inwardly in its central area, which does not have acentral hole and which has a relatively thin, puncturable central areawhich tapers to a thicker peripheral area. Positioned within the shellover and behind this end wall is a rubber disc which may also be concavein its central area to correspond in contour with the puncturable endwall of the aluminum shell. Such a construction provides a cleaner,safer and very simple closure.

Other objects and advantages of the present invention will becomeapparent from the following description of certain embodiments of theinvention with reference to the accompanying drawings in which FIG. 1 isa section in elevation of a conventional cartridge type syringe loadedwith a cartridge having an improved closure cap which embodies thepresent invention and showing a sterile hub-type disposable needle inposition to be attached to the syringe. The entrant end of the needlehas a slidably fitted sleeve mounted thereon of the type referred to inthe above-mentioned co-pending patent application.

FIG. 2 is an enlarged section of the lower end of the syringe of FIG. 1after the needle has been attached to the syringe in operating position.The needle has penetrated the closure cap and the sleeve has been pushedback on the needle. The concavity of the end wall of the closure cap ofthe cartridge is preferably deep enough and wide enough to accommodatethe flange at the leading end of the sleeve to thereby prevent jammingof the flange against the floor of the syringe barrel when it is pushedback along the needle by insertion of the cartridge.

FIG. 3 shows the packaged needle before it is inserted in the syringe.

FIG. 4 is like FIG. 2 but shows a modification of the syringe to preventthe sleeve from being caught in the syringe so that it cannot bewithdrawn from the syringe with the needle. This is achieved by thestrongly tapered floor of the barrel which also permits quick removal ofany droplets of moisture by shaking or by an air blast and createssubstantial space between said floor and the center of the closure cap.

In all the drawings, the numeral 1 designates a conventional cartridgetype syringe, 2 the barrel thereof, 3 the externally threaded needlereceiving tip thereof having a needle receiving passage 3a and 4sterilized cartridge containing the medication and adapted to beremovably inserted (loaded) in the syringe barrel.

The numeral 8 represents an improved puncturable closure cap embodyingthe present invention and attached to the lower end of the cartridge. Itcomprises (1) the metal shell 9 having a puncturable, smoothlycontoured, inwardly concave end wall 9a, which is thin at thepuncturable center area (in the order of about two thousandths of aninch thick) and gradually tapers to a thicker peripheral area (in theorder of about eight thousandths of an inch thick), and side wall 9bwhich is clamped to the lower end of the cartridge by rolling the endthereof over the lower lip of the cartridge, as shown, and (2) apuncturable rubber sealing disc which is located behind end wall 9a,which is also inwardly concave to conform to the end wall 9a, which mayalso be thin at its central puncturable area opposite the thin centralarea of end wall 9a and taper into a thicker peripheral area oppositethe thicker peripheral area of end wall 9a, and the periph cry of whichis wedged tightly between the periphery of end wall 9a and the lower endof the cartridge as shown.

The numeral 5 represents the hypodermic needle sharpened at both endsand 6 the plastic hub which is preferably internally threaded and firmlysecured to the needle in a conventional manner by the metal attachingmeans 7 and which is adapted to be threaded over the tip 3 to secure theneedle to the syringe, as shown in FIG. 2. Plastic hubs are sometimesattached directly to the needle without the metal intermediate 7.However, a firmer attachmentmay be secured by the use of an intermediatemetal piece 7. Also, hubs made completely of metal are often used.

It is preferred that the upper end of the hub 6 at 17 be unthreaded andcorrespond in inside diameter to the outside diameter of the tip 3 of astandard syringe with which the needle is to be used so that it slidablyfits over such tip. This makes for easier, faster and more accurateattachment of the hub to the syringe. We have found that plastic hubs donot always get started perfectly and the plastic thread is easilydamaged, therefore, we prefer to provide a short, unthreaded lead 17.

The numeral 12 represents a sleeve fitted snugly but slidably over thecartridge entrant end of the needle. The sleeve is of the type describedin said co-pending application and has a rearwardly and outwardlyextending flange 13 at the leading end thereof. The sleeve extendsslightly beyond the end of the needle, as shown. The leading end of thebore of the sleeve tapers outwardly slightly at 20 before it is bentback to form the rearwardly and outwardly extending flange 13. Theflange may be notched as described in said co-pending application. Theflange spaces the open leading end of the sleeve and hence the end ofthe needle away from the wall of the needle receiving passage 3a in thesyringe tip when the needle with the sleeve attached thereto, as shownin FIG. 1, is inserted in and through such passage to the position shownin FIG. 1 to insure against contamination. The slight outward flare 20spaces the leading end edge of the sleeve radially outwardly withrespect to the end of the needle to further protect it in the event suchedge is accidentally contacted. The rear end of the sleeve is taperedslightly outwardly at 20a.

The numerals 15 and 16 represent the cap and hood, respectively, of thepackage 16a for the sterilized needle and its sleeve. The package isassembled with the needle and sleeve therein, as shown, by screwing thecap 15 to the hub 6 and mounting the hood 16 on hub 6 by a friction fit.Both 15 and 16 are sealed to hub 6 at their margins after being afiixedto 6.

As aforesaid, generally, the sterilized cartridge is inserted into thebarrel of the syringe through the top as in the breech type of syringeor through a. long opening in the side of the syringe. Both types are incommon use in the dental profession. In either type the central area ofthe cap at the lower end of the sterilized cartridge, which is puncturedby the needle may be contaminated during insertion of the cartridge bycontact with the syringe in the syringe has not been completelysterilized or has become contaminated before use. Since the cartridgeentrant end of the needle comes in contact with this area of the closurecap, freedom from contamination is essential. The concavity in the capshown in the drawings prevents contact of the area of the cap to bepunctured with any part of the barrel of the syringe by bridging sucharea to thereby insure against contamination.

The depth of the concavity in the end wall 9a is preferably greater than(at least as great as) the height of the flange 13, i.e. the verticaldistance between the leading end of the sleeve and the trailing end ofthe flange, and the width of the concavity is preferably wider than (atleast as wide as) the widest portion of the flange (the trailing end) sothat the entire flange is contained within the concavity, as shown inFIG. 2 to insure against the flange being jammed against the bottom 22of the barrel when the cartridge is inserted into the syringe and forcesthe sleeve to slide backwardly along the needle. Thus, the concavityforms a chamber or housing for the flange when the needle is attached tothe syringe in its operative position.

The concavity not only protects the central punctured area of the endwall 9a against contamination and prevents jamming of the flange againstthe bottom of the barrel but it also serves to guide the forward end ofthe needle and sleeve to the thin center of such end wall.

The cartridge entrant end of the needle is protected from contact withthe wall of the needle receiving passage 3a in the tip of the syringe bythe sleeve 12 which, as aforesaid, is slidably aflixed thereto andextends beyond the end of the needle. The attachment of the sleeve tothe needle is snug enough to resist accidental displacement duringinsertion of the needle with the sleeve attached thereto through theneedle receiving passage of the syringe tip, but permits displacementbackwardly along the needle by engagement of the leading end of thesleeve with the puncturable end wall 9a of the closure cap (1) when thepuncturable end wall 9a is forced over the point of the needle duringinsertion of the cartridge into the syringe to the position shown inFIG. 2 after the needle with the sleeve thereon has been inserted to itsultimate position (FIG. 2) in the syringe, as usually practiced, or (2)when the needle is pushed through such end wall of the pre-positionedcartridge from the position shown in FIG. 1 to the position shown inFIG. 2.

In use, the sterilized cartridge 4 may be loaded in the syringe. The cap15 of the sterilized package containing the sterilized needle and sleeveattached thereto, is removed from the hub 6 and by grasping the hub 6with the fingers, the exposed end portion of the needle with the sleeveattached thereto is inserted in the needle receiving passage 3a until itreaches the position shown in FIG. 1 in which the leading end of thesleeve engages the puncturable end wall 9a, whereafter further insertionof the needle causes the sleeve to be pushed backwardly along the needleand the needle to puncture the central thin, recessed area of the endwall and move to the position shown in FEG. 2 at which the hub 6 isscrewed tightly on the tip 3 of the syringe. Thereafter, the hood 16 ispulled off the hub 6 and the syringe is ready for use. Usually however,the needle with the sleeve thereon is attached to the syringe in itsultimate position shown in FIG. 2 before the cartridge is placed in thesyringe in which case insertion of the cartridge in the syringe willforce the sleeve back along the needle and will cause the exposed end ofthe needle to puncture the thin central recessed area of the end wall9a.

In FIG. 4 the floor 22a of the syringe barrel is sloped inwardly anddownwardly for greater protection against contamination and otheradvantages as explained above.

It is usual practice to keep cartridges in alcohol just before use. Itis good practice to shake the cartridge and then quickly flame theclosure end before inserting it into the barrel of the syringe. For thisreason, it is preferable that the aluminum shell 9, which functions as aclamping member, cover the rubber seal and that it be one piece so as toprovide a smooth continuous surface. Furthermore, the continuous smoothcontour of the external surface of the metal cap of the presentinvention eliminates crevices and corners in which bacteria or otherharmful organisms can accumulate. We have referred to the aluminumclamping member or shell as being made of aluminum merely because it isthe most commonly used material and is quite suitable for the purpose.However, other materials may be used.

Furthermore, where we have described the use of our invention for sealedcartridges containing measured doses of medicants, it may, of course, beused to aspirate into an empty cartridge.

Although the closure cap shown in the drawings has an end wall comprisedof two layers, we do not limit our invention to any particular number.

Although we illustrate and we prefer to thread the needle hub to thesyringe tip other conventional means may be used, for example, the Luerlock or a tight tapering fit.

It is not intended that the invention be limited to the exact structuresdescribed and shown, such structures being for illustrative purposesonly.

This application is a continuation-in-part of said 00- peudingapplication Serial No. 835,802, now Patent No. 3,055,364.

We claim:

1. In combination, a cartridge and syringe having a barrel, saidcartridge being removably placed in said barrel and having a needlepuncturable closure cap at one end, a hypodermic needle extendingthrough a needle receiving passage in said syringe to said closure capof said cartridge and having a slidable sleeve normally mounted with aslidable friction fit around the cartridge entrant end of said needle,said cartridge entrant end of said needle being adapted to be insertedwith said sleeve therearound into said needle receiving passage in saidsyringe to said closure cap, said cap comprising a seal and a clampingmember having a needle puncturable wall overlying said seal, thecircumferential surface area of said clamping member protruding belowits central needle puncturable area to provide a centrally recessed areato prevent contact of said needle puncturable area with the syringe saidsleeve being slidable back on said needle by engagement with saidrecessed area to expose said cartridge entrant end of said needle, saidneedle puncturable area being pierced by said exposed entrant end ofsaid needle with said sleeve slid back on said needle to a positionintermediate the ends of said needle and outside said closure cap, saidrecessed area being concave inwardly, said slidable sleeve having aflange at its leading end, said concave recess being deep enough andwide enough to receive said flange.

2. In combination, a cartridge and a syringe having a barrel in whichsaid cartridge is received for use with a hypodermic needle having aslidable sleeve located over its cartridge entrant end, said cartridgehaving a centrally puncturable closure cap at one end adjacent the floorof said barrel, said closure cap comprising a seal and a clamping memberhaving a centrally needle puncturable wall overlying said seal, saidwall being recessed inwardly, the fioor of said barrel slopingdownwardly to form with said recess a housing, said syringe including aneedle receiving passage leading to said barrel, said combination alsoincluding a hypodermic needle having a cartridge entrant end and apatient entry end and having a slidable sleeve normally mounted with aslidable friction fit around said cartridge entrant end of said needle,said cartridge entrant end of said needle being adapted to be insertedwith said sleeve therearound into said needle receiving passage, saidsleeve being slidable back on said needle by engagement with saidrecessed portion of said clamping member, said needle being located insaid needle receiving passage with said needle puncturable area beingpierced by said exposed entrant end of said needle and said sleeve beingslid back on said needle and located in said housing.

3. A combination according to claim 2, the leading end of said sleevehaving a flange extending outwardly and rearwardly therefrom, the depthand width of said housing being greater than the height and width,respectively, of said flange, said flange being located in said housing.

4. A combination according to claim 2, the central areas of said sealand overlying wall being concaved inwardly and being thinner than theperipheral areas thereof, the concave outer surface of said Wall of saidclamping member being smoothly contoured and continuous.

S. A cartridge for use with a hypodermic syringe, said cartridge havinga needle puncturable closure cap over an opening at one end, the otherend of said cartridge having a closure stopper fitted tightly butslidable therein, said stopper being adapted to be propelledlongitudinally within said cartridge to expel the contents of saidcartridge through said one end, said closure cap comprising a clampingmember and a sealing member extending across said opening at said oneend of said cartridge, the portion of said sealing member across saidopening being displaced inwardly to form an inwardly curved concavity,said clamping member having a centrally puncturable wall extendingacross said opening and overlying said concave sealing member, theportion of said wall across said opening also being displaced inwardlyto form an inwardly, smoothly and continuously curved concavity ofrelatively shallow curvature similar in contour to said sealing memberand extending over an area corresponding to the area of said opening toprovide across said opening a concave, centrally needle puncturable areawhich is protected from contact with said syringe, said clamping memberbeing of one piece and the outer surface of said wall thereof beingsmoothly contoured and continuous thereacross.

6. A cartridge according to claim 5, said concave wall of said clampingmember being thinner at its central area than at its peripheral area.

7. In combination, a cartridge according to claim 5, a syringe having abarrel, said cartridge being removably placed in said barrel, and ahypodermic needle having a cartridge entrant end and a slidable sleevenormally mounted with a slidable friction fit around said cartridgeentrant end, said cartridge entrant end being adapted to be insertedwith said sleeve therearound into a needle receiving passage in saidsyringe to said closure cap, said sleeve being slidable back on saidneedle by engagement with said concave centrally needle puncturable areato expose said cartridge entrant end of said needle, said centrallyneedle puncturable area being pierced by said exposed entrant end ofsaid needle with said sleeve slid back on said needle to a positionintermediate the ends of said needle and outside said closure cap.

8. A cartridge for use with a hypodermic syringe, said cartridge havinga needle puncturable closure cap over an opening at one end, the otherend of said cartridge having a closure stopper fitted tightly butslidable therein, said stopper being adapted to be propelledlongitudinally within said cartridge to expel the contents of saidcartridge through said one end, said closure cap comprising a clampingmember and a sealing member extending across said opening at said oneend of said cartridge, said clamping member having a centrallypuncturable wall extending across said opening and overlying saidsealing member, the portion of said wall across said opening beingconcave inwardly over an area corresponding to the area of said openingto provide across said opening a concave, centrally needle puncturablearea which is protected from contact with said syringe, the outersurface of said concavity being smooth and uninterrupted throughout, theinner and outer surfaces of said concave portion of said wall convergingtowards each other from the periphery of said concavity to the centerthereof to form a thin, easily puncturable center.

9. In combination, a cartridge and a syringe having a barrel in whichsaid cartridge is received for use with a hypodermic needle having aslidable sleeve located over its cartridge entrant end, said cartridgehaving a puncturable closure cap over an opening at one end thereofadjacent the floor of said barrel, said closure cap comprising a sealingmember extending across said opening and a clamping member having acentrally needle puncturable wall extending across said opening andoverlying said sealing member, the portion of said wall across saidopening being displaced inwardly to form an inwardly curved concavity ofsmooth and shallow curvature across said opening extending over an areacorresponding to the area of said opening and being smoothly contouredand continuous thereacross, the floor of said barrel sloping downwardlyto form with said concavity in said closure membet a housing.

References Cited in the file of this patent UNITED STATES PATENTS744,617 Ritsert Nov. 17, 1903 2,007,454 May July 9, 1935 2,020,828Goldberg Nov. 12, 1935 2,022,369 Curtis Nov. 26, 1935 2,429,183 GoldbergOct. 14, 1947 2,460,641 Kleiner Feb. 1, 1949 2,789,559 Breitenbach Apr.23, 1957 2,986,141 Hart May 30, 1961 3,055,364 Myerson et a1 Sept. 25,1962 3,092,108 Friedman June 4, 1963

1. IN COMBINATION, A CARTRIDGE AND SYRINGE HAVING A BARREL, SAIDCARTRIDGE BEING REMOVABLY PLACED IN SAID BARREL AND HAVING A NEEDLEPUNCTURABLE CLOSURE CAP AT ONE END, A HYPODERMIC NEEDLE EXTENDINGTHROUGH A NEEDLE RECEIVING PASSAGE IN SAID SYRINGE TO SAID CLOSURE CAPOF SAID CARTRIDGE AND HAVING A SLIDABLE SLEEVE NORMALLY MOUNTED WITH ASLIDABLE FRICTION FIT AROUND THE CARTRIDGE ENTRANT END OF SAID NEEDLE,SAID CARTRIDGE ENTRANT END OF SAID NEEDLE BEING ADAPTED TO BE INSERTEDWITH SAID SLEEVE THEREAROUND INTO SAID NEEDLE RECEIVING PASSAGE IN SAIDSYRINGE TO SAID CLOSURE CAP, SAID CAP COMPRISING A SEAL AND A CLAMPINGMEMBER HAVING A NEEDLE PUNCTURABLE WALL OVERLYING SAID SEAL, THECIRCUMFERENTIAL SURFACE AREA OF SAID CLAMPING MEMBER PROTRUDING BELOWITS CENTRAL NEEDLE PUNCTURABLE AREA TO PROVIDE A CENTRALLY RECESSED AREATO PREVENT CONTACT OF SAID NEEDLE PUNCTURABLE AREA WITH THE SYRINGE,SAID SLEEVE BEING SLIDABLE BACK ON SAID NEEDLE BY ENGAGEMENT WITH SAIDRECESSED AREA TO EXPOSE SAID CARTRIDGE ENTRANT END OF SAID NEEDLE, SAIDNEEDLE PUNCTURABLE AREA BEING PIERCED BY SAID EXPOSED ENTRANT END OFSAID NEEDLE WITH SAID SLEEVE SLID BACK ON SAID NEEDLE TO A POSITIONINTERMEDIATE THE ENDS OF SAID NEEDLE AND OUTSIDE SAID CLOSURE CAP, SAIDRECESSED AREA BEING CONCAVE INWARDLY, SAID SLIDABLE SLEEVE HAVING AFLANGE AT ITS LEADING END, SAID CONCAVE RECESS BEING DEEP ENOUGH ANDWIDE ENOUGH TO RECEIVE SAID FLANGE.